This invention relates to an apparatus for energizing a semiconductor laser array having a plurality of light beam emitting points and, in particular, to an apparatus for energizing a semiconductor laser array used in an information retrieving system having an optical memory on which light beams are converged, and controlling the laser beams emitted from the semiconductor laser array.
An information retrieving system is known in the art which, with the use of a plurality of light beams reflected from an optical memory on which they are initially converged, retrieves information recorded on the optical memory. This type of information retrieving system is known, for example, in U.S. Pat. Nos. 673,764; 705,305; and 713,598, filed on Nov. 21, 1984; Feb. 25, 1984; and Mar. 19, 1985, respectively. The information retrieving system may be of a read-while-erase type, a write-after-erase type, read-while-write type or a write-while-read type. In this case, a semiconductor laser is used as a light source for the information retrieving system and, in recent times, a semiconductor laser array has been developed having a plurality of laser structures and of light emitting points. This semiconductor laser array has been studied for the possibility of being used as a light source. Since, however, the semiconductor laser array of such type includes a close proximity array of laser structures as well as a close proximity array of light beam emitting points, if laser beams are emitted from the light beam emitting points through the energization of the laser structures, cross-talking occurs among the laser beams at which time an unstable beam or beams emerge from the light beam emitting points and may sometimes be oscillated. Furthermore, even if the ambient temperature around the semiconductor laser array varies, problems also occur because of a variation in the operation characteristics of the laser structures and because the beam or beams emitting from the light beam emitting points vary depending upon the ambient temperature.